A rotary shaft of a motor is connected to an actuator to transmit a driving force thereto. At this time, the motor and the actuator can be integrally manufactured according to characteristics of the actuator. For example, a driving shaft of the actuator and a rotary shaft of the motor can be integrally formed by forming the motor and the actuator together in one housing or using a tube-type rotor. In addition, a control module configured to control the motor according to a state of the actuator can be provided.
However, the motor having such a structure has a problem in that a size of the motor is increased due to the tube-type rotor. In addition, sensors configured to measure the state of the actuator are connected to the control module, but an operation of connecting the sensors to the control module is difficult and a connecting structure thereof is complex, and thus there is a problem in that reliability of sensed information is reduced.
Particularly, since the driving shaft of the actuator and the rotary shaft of the motor are integrally formed, there are problems in that precise position control is difficult, and compatibility of component replacement is reduced. In addition, since a large-sized bearing is installed at a side of the motor to overcome a load acting on the actuator, there is a problem in that the size of the motor is increased.